Foamed lightweight refractory monolithic composition

Abstract

A foamed lightweight monolithic refractory castable is provided. The castable includes one or more refractory aggregates as a main constituent, one or more foaming additives in a range of 0.1 wt % to 3.0 wt %, one or more cellulosic powder air-entraining additives in a range of 0.005 wt % to 2.0 wt %, one or more binders in a range of 1 wt % to 40 wt %, and one or more superplasticizers in a range of 0.05 wt % to 0.5 wt %. The refractory aggregates include at least one of alumina and silica. The foaming additives include at least one of alkylbenzene sulfonates, alkene sulfonates, and hydroxylalkane sulfates. The superplasticizers include at least one of sodium polyacrylates, naphthalene sulfonates, polyethylene glycols, polycarboxylates, polyacrylates, and polycarboxylate ethers.

Having described the invention, the following is claimed: 
     
         1 . A foamed lightweight monolithic refractory castable, comprising:
 one or more refractory aggregates as a main constituent, the refractory aggregates comprising at least one of alumina and silica;   one or more foaming additives in a range of 0.1 wt % to 3.0 wt %, the foaming additives comprising at least one of alkylbenzene sulfonates, alkene sulfonates, and hydroxylalkane sulfates;   one or more cellulosic powder air-entraining additives in a range of 0.005 wt % to 2.0 wt %;   one or more binders in a range of 1 wt % to 40 wt %; and   one or more superplasticizers in a range of 0.05 wt % to 0.5 wt %, the superplasticizers comprising at least one of sodium polyacrylates, naphthalene sulfonates, polyethylene glycols, polycarboxylates, polyacrylates, and polycarboxylate ethers.   
     
     
         2 . The castable of  claim 1 , wherein the refractory aggregates further comprise at least one of kyanites, pyrophillites, silica sands, dolomites, and magnesias. 
     
     
         3 . The castable of  claim 2 , wherein the refractory aggregates further comprise at least one of expanded clay aggregates, fireclays, mullites, chamottes, bauxites, and high-purity aluminas. 
     
     
         4 . The castable of  claim 1 , wherein the castable is a ready-mix formulation. 
     
     
         5 . The castable of  claim 1 , further comprising:
 one or more accelerants in a range of 0.01 wt % to 0.25 wt %, the accelerants comprising at least one of lithium fluoride, lithium citrate, calcium hydroxide, and sodium silicate.   
     
     
         6 . The castable of  claim 1 , further comprising:
 one or more acidic compounds in a range of 0.03 wt % to 0.2 wt %.   
     
     
         7 . The castable of  claim 1 , further comprising:
 one or more rheology modifiers in a range of 0.05 wt % to 0.15 wt %, the rheology modifiers comprising at least one of polypropylene fibers, xanthan gums, and bentonite.   
     
     
         8 . The castable of  claim 1 , wherein the binders comprise one or more calcium aluminate binders. 
     
     
         9 . The castable of  claim 1 , wherein the cellulosic powder air-entraining additives comprise one or more of methylcellulose and methylhydroxypropylcellulose. 
     
     
         10 . A method of applying a foamed lightweight monolithic refractory castable to a surface, the method comprising:
 assembling a ready-mix formulation for the foamed lightweight monolithic refractory castable, the ready-mix formulation including one or more refractory aggregates as a main constituent, one or more foaming additives in a range of 0.1 wt % to 3.0 wt %, one or more cellulosic powder air-entraining additives in a range of 0.005 wt % to 2.0 wt %, one or more binders in a range of 1 wt % to 40 wt %, and one or more superplasticizers in a range of 0.05 wt % to 0.5 wt %, the refractory aggregates including at least one of alumina and silica, the foaming additives including at least one of alkylbenzene sulfonates, alkene sulfonates, and hydroxylalkane sulfates, the superplasticizers including at least one of sodium polyacrylates, naphthalene sulfonates, polyethylene glycols, polycarboxylates, polyacrylates, and polycarboxylate ethers;   mixing the ready-mix formulation with water to form the foamed lightweight monolithic refractory castable; and   spraying the foamed lightweight monolithic refractory castable onto the surface.   
     
     
         11 . The method of  claim 10 , wherein the refractory aggregates further include at least one of kyanites, pyrophillites, silica sands, dolomites, and magnesias. 
     
     
         12 . The method of  claim 11 , wherein the refractory aggregates further include at least one of expanded clay aggregates, fireclays, mullites, chamottes, bauxites, and high-purity aluminas. 
     
     
         13 . The method of  claim 10 , wherein the ready-mix formulation further includes one or more accelerants in a range of 0.01 wt % to 0.25 wt %, the accelerants including at least one of lithium fluoride, lithium citrate, calcium hydroxide, and sodium silicate. 
     
     
         14 . The method of  claim 10 , wherein the ready-mix formulation further includes one or more acidic compounds in a range of 0.03 wt % to 0.2 wt %, 
     
     
         15 . The method of  claim 10 , wherein the ready-mix formulation further includes one or more rheology modifiers in a range of 0.05 wt % to 0.15 wt %, the rheology modifiers including at least one of polypropylene fibers, xanthan gums, and bentonite. 
     
     
         16 . The method of  claim 10 , wherein a percentage of water by weight of the foamed lightweight monolithic refractory castable is in a range of 15 wt % to 35 wt %. 
     
     
         17 . The method of  claim 10 , further comprising, after the mixing:
 setting the foamed lightweight monolithic refractory castable in a range of 2 hours to 24 hours.   
     
     
         18 . The method of  claim 17 , further comprising:
 curing the sprayed foamed lightweight monolithic refractory castable on the surface.   
     
     
         19 . The method of  claim 10 , wherein the spraying of the foamed lightweight monolithic refractory castable comprises shotcreting the foamed lightweight monolithic refractory castable 
     
     
         20 . The method of  claim 10 , wherein the binders comprise one or more calcium aluminate binders.